Speed-indicating machine.



e indicate b' enteren SOLOMON A. CAMPBELL, O

FA CTURI N G GL 1A.

dll'll'llt'iOll'N, MA SSMlllSEWlS, ASSIGNOR TO PARKER MANU- COML'ANY, Ol BOSTON, MASSA(`ltlSlC'lTS, A CORPORATION OF WEST VIR- SPEED-NDICATING MACHINE.

Specification of Letters Patent.

Patented July 13, 1.909.

Application filed .Tune l0, 1907. Serial No. 378,091.

To all '2n/rom. t 'ma 1/ conca/nx Be it vknown that l, SoLoMoN AMCAMP- nnLL, olf ll'atertown, in the county ot Middlesex and State ot Massachusetts, have invented certain new and useful Improvements in Spced-indicating islzleliiiies, olf which the ii-nlowiur4 is a speciiication.

This invention relates to machines adapted l to be operated by a rotating element, and lo a cooperating pointer and dial, the rate et speed at which the rotating element nieves. A machine et this type, com- `monty called speedometer when used with a motor vehicle, to show the rate oft' 5 Speed at which the vehicle travels, ought to produce what is termed an even reading,` that is, equal units of movement oi" the pointer for equal units of speed oi the rotating element, such as the wheel ojt a vehicle. e To that end the present invention consists of an indicating mechanism actuated by a centrifugally-operated mechanism, which in turn is driven by the rotating element whose rate ot' speed is to be indicated. 'lhe cen- 5 trilugally-operated mechanism includes weights, each adapted to turn about an individual pivot mounted in bearings which rotate with, and as a partot, the rotatingI element. When this element rotates, the i weights, by reason oi centrifugal force, have a tendency to turn about their individual pivots so as to recede troni each other.

Une oll the essential teal uresoit the present invention is the means for transmittiivt;l to t the pointer the movement. imparted to the weights by centrifugal torce. This transmitting means .is .so constructed that it receives a. unit of movement iter each unit el." movement oi the weights relatively to their individual pivots, and transmits such movement by equal units Vto the pointer. In many machines oi this type, the transmittin5 5A mechanism receives from the rotating elcn'ient, units ot movement which vary, and so are not in .proportion to those oi the rotating element. This variation is in some machines caused by connections which operate through varying angles, and it may be seen in the present .invention that lno angular mot-ions are employed in the transmitting mechanism.

JAnother in'iportant 'feature is the means employed to apply spring tension to oppose the centrifugal movement oi the Weights.

This tension is applied to radial arms` or levers which move 'willi the weights, and the arms are so arranged that when in normal position they are in alim-.ment with the line o'li tension. As the angles of the weights change, the. angles of the spring-held arms change in such manner thatthe leverage atlorded the springs varies directly as the centrifugal movement.. ot' the weights.

Referring now lo the accompanying' drawings forming a part ot' this speclcation,- Figure 1t' is a top plan view oi a speedometer constructed in accordance with my invention. Fig'. Q is a cross section thereof on a plane directly below the dial. Fig. Il is an elevatiom-and Fig. is a section ol the casing on line that oi Fig. 3, with the mechanism in elevation. Fig. 5 is a cross lsection on line 5-5 of Fig( fl,

The same reference characters indicate the same parts wherever they occur.

l0 is a rotatable sha'tt journaled in a suitable bearing` ot the casing ll. 'lhc easing has an ear 1&2 by which it may be atlixed to a support, and a flexible tube ll inelosing a llexible drive sha'l't ,lll connected to the outer end of the shaft it). The shaft l0 is provided with collars lo which prevent it from moving' axially in relation to the casing, and with a pair ol dianwtrically opposite T brackets .lo ftt which rotate with it. The brackets are spaced sutlicicntly to permit the inlerposition ol.l a pair ot' weights i7 t7. ',lhe weights have truunions iS which are pivoted in diamctricall)v opposite bearings in the brackets, at equal distances t'rom the axis et tl'e shalt 1t), and they normally hang,l below their trunnions, and relatively close to the axis ot' the shalt. llhcn the shaft rotates, it carries with it the brackets and thc weights, the axes olr whose. trunnions extend in lines tangent to their circle of rotation about the shaft. By reason of the arrangement of the trunnions,` the weights are adapted to swing away from the shait to the. positions indicated by dotted lines in Fig. 4. llach weight, has an arm or lover 19 shown as adjustably clamped to a trunuion so as to turn with it'. The outer end et the arm is connected to one end of a helical spring.; 20, oill which the other end is connected to the protruding end oi a trullnion of the opposite weight. One arm 1t) and spring 20 are on one side of he axis of the shaft 10, and the other arm and spring are on the opposite. side` of the axis. By reason of this arrangement, the rotating element is evenly balanced at diametrically opposite points. Vhen the weights are in normal position, shown by full lines in gland 5, they may bear against stops 2l 2l which rotate with the shaft and prevent the weights from approaching too closely the common axis of rotation. ln this position the radius of each arm 1t) is in alinement with the direction of tension of its spring QQ, and consequently the spring has no leverage or effect tending to turn the weight about its individual axis. l3nt, on the other hand, when a maximum centrifugal force causes the weight to assume the angle shown by dotted lines, the arm l) assun'ies a corresponding angle, thereby affording its spring a maximum leverage, the tension of the spring then heing'in a line approximately at right angles to the radius of the arm. lt may therefore be seen that the leverage of the opposing force increases or decreases as well as the force itself, when the centrifugal effect on-the weights increases or decreases.

For transforming the hereindescribed centrifugal movement of the weights into an indicating movement, the weights are provided each with a series of teeth concentric to its individual axis.

Q6 is a cylindrical sleeve mounted on the shaft 10. Alt is free to move relatively thereto, either axially or rotatably. The sleeve is provided with a series'of peripheral annular ribs 2T which inter-mesh with the teeth 25 of the weights in the relation of a raclr and gears. ln another plane the ribs intermesh with the teeth of a gear 28 which is allixed upon a shaft- 29. The ends of this shaft are supported by fixed bearings, one of which is in an car 8() on a plate 3l, and the other in the exterior of a boss or sleeve permanently affixed to the said plate. The latter extends diametrically from one side of the casing 11 to the other, and has tongues 33 which interlock with aperturesl in the casino'. rl`he introduction of the tongues into the apertures is accomplished by slightly springing the casing. The bearing in the ear Z is in the form of a step 34 which is screwthreaded and therefore adjustable and removable. rlhe shaft 29 is further provided with a fixed bevel gear 35 intermeshing with a bevel gear 3G allixcd upon one end ot' a rotatable statin 37 journaled in the boss 32. T he staff extends through the boss and plate 31, and also through a dial 38 which lies against the plate and is secured in the casing in any suitable way. 'l`hat end of the staff which extends through the dial is provided with a hand or pointer fit), and the outer face of the dial has a gage or index consisting of a series of marks with which the pointer is adapted to cooperate as hereinafter explained. The dial and pointer are inclosed by a transparent cover 39 such as glass.

rl'he operation of the machine is as follows :klYhen the weights 17 are driven so as to rotate as a unit about their common axis as hereinbefore described, and the cen'-v trifugal force thus produced causes theln to change their angles, the teeth 25 of the weights move the sleeve 26 endwise in one direction. The endwise movement of the sleeve in'iparts rotative movement to the gear 28, shaft 2t), (fear 35, gear 36, staff 37 and pointer -lOL 11er convenience of description, the pointer and dial may be termed an indicator, and. the mechanism interposed between it and the toothed weights may be termed the transmitting mechanism or element. Altogether then, there is a rotating element, a transmitting element, and an indicator. By reason of employing intermeshing teeth and ribs for imparting movementto the transmitting mechanism, 4the latter receives equal units of movement for corresponding units of angular movement of the weights about their individual axes. A'nd by further employing intermeshing teeth at each place in the transmitting mechanism where a change of direction occurs, the ratio of movement of each part, relatively to that of its complemental part, is maintained throughout, so that finally, the indicator receives equal units of angular movement for corresponding units of angular movement which the weights receive from centrifugal force. lhe tendency of the spring 20 is, of course, always to draw the weights together and consequently to actuate the transmitting mechanism and indicator in the direction opposite to that in which centrifugal force operates. So, since the latter force and its opposing force counteract each other always at a pointl which fluctuates as the speed of the rotating element, the indicator is caused to show each fluctuation simultaneously and in exact proportion it ccurs. 'lhe rotating weights are analogous to a ball governor and, in fact, their positions relatively to their pivots do govern the position ol' the indicator.

l claim z- 1. A machine of the character described, comprising a rotatable element having pivoted toothed weights adapted to be turned on their pivots by centrifugal force of rotation of the element, suitable spring tension applied to said weights so as to oppose said force, a cylindrical member concentric with and adapted to move along the axis of said rotating element, andA having a series of annular peripheral ribs in intermeshed relation with said toothed weights, a relatively stationary element having a gear provided with teeth intermeshing with the ribs of ,said cylindrical member, and a movable indicator connected to said gear so as toibo actuated thereby.

:2. In a machine oil the character described, a rotatable element having pivoted toothed Weights adapted to be turned on their pivots by centrifugal force of rotation ot the clement, an axially-imvable cylinder located concentrically with relation to said clement, and having a series oLt' annular peripheral ribs intcrmeshing with tt e teeth of the weights, an indicator, means interlihscd vbetween said cylinder and .indicator for transmitting movement of one to the other, su1table spring members, and means carried by the weights and connected to said spring members, whereby the spring tension is caused to limit centrifugal movement of the weights in. proportion to the speed ot' the rotating element.

3)f Inamachine of the character described, a rotatable element, a toothed weight pivoted thereto,'a toothed sleeve movable axially on saidI rotatable element and cooperating with said toothed Weight to be moved thereby, an indicatorn'iovable in a plane substantially at right angles to the axial movement of said toothed sleeve, means actuated by said toothed sleeve i'or moving said indicator in one direction, and means to move said toothed weight in a direction opposite to that in which it is moved by rotation of said element.

4f, In a machine of the character described,

a rotatable element, a toothedisleeve aXially movable on said yrotat ble element, gears in mesh with said toothed sleeve, weights connected With said gears to effect axial movement of the said sleeve in response to lcentrifugal action upon said 'weights, an indicator, means actuated by 5. In a machine of the character described,

a rotatable element, a toothed sleeve axially movable on said element, gears pivoted to said rotatable element on substantially diamctrically opposite sides of the toothed sleeve, and having their teeth in engagement with said toothed sleeve, weights connected to said gears, levers or arms attached to the pivots of said gears and extended toward each other on opposite sides of the rotatable element, springs connected to said levers or armsto move the said gears Ato their starting position, an indicator, and means actuated by the toothed sleeve for operating said indicator, substantially as descri-bed.

In testimony whereof I. have affixed my signature, in resence of two Witnesses.

S LOMON A. CAMPBELL. Witnesses:

PETER W. PEZZE'r'rI, A. C. RATlGAN. 

